This invention relates generally to improvements in computer disk drives. More particularly, the present invention relates to a computer disk drive unit having an isolator disposed between a cover for the housing and a memory storage unit within the housing, for preventing direct contact and absorbing vibration between the housing cover and the memory storage unit.
In recent years microcomputer equipment, particularly personal and desk top computers, have become extremely popular for a wide variety of home, business and commercial uses. Such computers commonly include a main central processor unit having one or more memory storage disks. In many modern computers, the storage disk or disks, sometimes refer to as "hard disks," are provided as part of a Winchester-type disk drive unit having the storage disks supported in a stack on a rotary spindle within a substantially sealed disk drive housing. The disks are rotatably driven in unison by a small spindle motor, and one or more electromagnetic heads on a movable positioning arm are displaced by a precision stepper motor to traverse surfaces of the rotating disks for purposes of reading and writing data. Such Winchester-type disk drive units are generally preferred in comparison with so-called floppy type disk drives due to their higher memory storage capacities and faster operating speeds.
With the steadily increasing popularity of personal-sized computers, various standard computer components have evolved to accommodate installation into computers produced by different manufacturers and/or to ensure compatibility with commercially available software. In this regard, Winchester-type disk drive units having one or more memory storage disks of an approximate 5.25 inch diameter have been manufactured and used on an industry-wide basis. More recently, smaller and lighter Winchester-type disk drives having storage disks of about 3.74 inches in diameter have become available. For either diametric size, the disk drive units have been produced in standardized vertical profile sizes to permit installation into a computer as an original equipment item, or as an after-market item to replace or upgrade an original disk drive unit. Disk drive units have been manufactured with a vertical dimension of about 3.25 inches to fit within a so-called "full height" vertical spacing, or with a vertical dimension of about 1.625 inches to fit within a so-called "half height" profile.
Typically, such computer disk drive units include a housing having a lower base and an upper removable cover which, collectively, define a disk storage compartment therebetween. A shaft is fixed to the lower base and extends upwardly therefrom toward the upper housing cover, and one or more memory storage disks are mounted for rotation within the disk storage compartment about the shaft. The shaft and the memory storage disks comprise a memory storage unit which, with other related components situated within the disk storage compartment, are manufactured to very precise manufacturing specifications in order to, in many instances, maximize the memory storage capabilities of the disk drive unit.
The upper housing cover is usually quite thin and, under certain circumstances, capable of flexing inwardly and outwardly relative to the disk storage compartment. This can be a problem in an operating environment if inward flexion of the cover causes the cover to contact a moving component of the memory storage unit within the disk storage compartment. One solution, as illustrated in U.S. Pat. No. 4,905,110, the contents of which are incorporated herein by reference, has been to secure the cover directly to a shaft of the spindle motor in order to attempt to eliminate movement of the cover relative to the rotating memory storage disks, and thereby prevent contact. One disadvantage to this approach, however, is that sometimes undesirable vibration occurs between the cover the shaft.
Accordingly, there has been a need for a novel computer disk drive unit wherein direct contact between the shaft and the upper housing cover is prevented. Moreover, such a disk drive unit is needed wherein relative vibration between the shaft and the upper housing cover is absorbed. Such an improved disk drive unit must utilize, to the extend possible, standard housing and memory storage unit components, and lend itself to economical manufacturing processes and techniques. The present invention fulfills these needs and provides other related advantages.